A method for pulse current assisted micro-straightening of a titanium alloy welded pipe of an aero-engine

Abstract

A kind of aviation engine titanium alloy welded pipeline pulse current auxiliary micro-calibration method, steps are as follows: manufacturing calibration tooling;Titanium alloy welded pipeline is fixedly clamped to calibration tooling in the inside while completing pipeline cold calibration positioning;Electrode is installed at the both ends of titanium alloy welded pipeline calibration section;Electrode is connected through wire into direct current pulse power supply;Start direct current pulse power supply, and the calibration section of titanium alloy welded pipeline is heated by pulse current;The calibration section of titanium alloy welded pipeline is measured by temperature measuring instrument in real time until the real-time temperature of the calibration section of titanium alloy welded pipeline reaches set value;The calibration section of titanium alloy welded pipeline is kept at set temperature value for a set time;Direct current pulse power supply is closed, and heating of the calibration section of titanium alloy welded pipeline is ended until the temperature of the calibration section of titanium alloy welded pipeline cools to normal temperature;Titanium alloy welded pipeline is removed from calibration tooling, and pulse current auxiliary micro-calibration of titanium alloy welded pipeline ends.

Description

Technical Field

[0001] The invention belongs to the technical field of aero-engine component manufacturing, and in particular relates to a pulse current assisted micro-correction method for aero-engine titanium alloy welding pipeline. Background Art

[0002] Titanium alloy, with its advantages of low density, corrosion resistance, and high strength, has become a key material for aircraft and aero-engines. The piping system is a crucial component of an aero-engine, carrying the fuel, lubricating oil, air, and other media required for its operation and also ensuring the implementation of functions such as engine system control and condition monitoring. With the increasing thrust-to-weight ratio requirements of new-generation aero-engines, reducing the weight of external piping is crucial for improving aero-engine performance. Therefore, the use of titanium alloy as a piping system material has become an inevitable trend in aero-engine design and manufacturing.

[0003] However, due to the complex functions and characteristics of the piping system, the manufacturing process of titanium alloy piping involves not only bending and forming, but also connection and assembly processes, which are prone to problems such as out-of-tolerance or shape changes. Micro-calibration is required, and only after meeting the dimensional accuracy requirements can it be installed. Therefore, how to achieve precise manufacturing of titanium alloy piping and overcome the lack of manufacturing precision has become a pressing bottleneck that needs to be solved.

[0004] Currently, micro-shaping of titanium alloy welded pipes is primarily performed manually at room temperature, with the degree of shaping heavily dependent on the operator's experience. However, due to the low elastic modulus and high yield strength of titanium alloys, their elastic deformation is large, resulting in low shaping efficiency and poor shaping accuracy. While micro-shaping using an integral heat treatment can improve shaping accuracy, the integral heat treatment suffers from the drawback of long thermal cycling times, which can easily deteriorate the microstructure and mechanical properties of the titanium alloy pipes. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides a pulse current assisted micro-shaping method for titanium alloy welding pipelines of aircraft engines, which introduces pulse current assisted forming technology into the micro-shaping of titanium alloy pipelines. The pulse current only generates Joule heating effect and electroplastic effect in the local area where the shaping section of the titanium alloy pipeline is located, which can avoid the deterioration of the overall microstructure and mechanical properties of the titanium alloy pipeline, and at the same time greatly improve the shaping efficiency and shaping accuracy of the titanium alloy pipeline.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a pulse current assisted micro-straightening method for titanium alloy welding pipelines of aircraft engines, comprising the following steps:

[0007] Step 1: Make the shape correction tool;

[0008] Step 2: Fix the titanium alloy welded pipe into the shaping fixture and complete the cold shaping positioning of the titanium alloy welded pipe at the same time;

[0009] Step 3: Install a first electrode and a second electrode at both ends of the shaping section of the titanium alloy welding pipe;

[0010] Step 4: Connect the first electrode and the second electrode to the positive and negative poles of a DC pulse power supply respectively through wires;

[0011] Step 5: Start the DC pulse power supply and heat the shaping section of the titanium alloy welding pipe through the pulse current;

[0012] Step 6: Use a thermometer to measure the temperature of the shaping section of the titanium alloy welded pipe in real time until the real-time temperature of the shaping section of the titanium alloy welded pipe reaches the set value;

[0013] Step 7: Keep the shaped section of the titanium alloy welded pipe at the set temperature for a set time;

[0014] Step 8: Turn off the DC pulse power supply to end the heating of the titanium alloy welding pipe shaping section until the temperature of the titanium alloy welding pipe shaping section cools to room temperature;

[0015] Step 9: Remove the titanium alloy welding pipe from the shaping tooling, and the pulse current assisted micro-shaping of the titanium alloy welding pipe is completed.

[0016] The shape correction tool is divided into a micro-straightening tool and a micro-bending tool.

[0017] The micro-straightening tool comprises a micro-straightening tool base plate, a micro-straightening pipeline fixed support, a micro-straightening pipeline fixed pressure plate, a micro-straightening pipeline fixed tightening screw, a micro-straightening pipeline auxiliary positioning support seat, a pipeline micro-straightening reaction force support seat and a pipeline micro-straightening force screw; the micro-straightening pipeline fixed support, the pipeline micro-straightening reaction force support seat and the micro-straightening pipeline auxiliary positioning support seat are fixedly installed on the upper surface of the micro-straightening tool base plate in a straight line sequence; the micro-straightening pipeline fixed pressure plate is arranged on the top of the micro-straightening pipeline fixed support, and the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support are connected by the micro-straightening pipeline fixed tightening screw, the titanium The non-alignment section of the alloy welded pipeline passes between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support; a pipeline auxiliary positioning groove is provided on the top of the micro-straightening pipeline auxiliary positioning support seat, and the non-alignment section of the titanium alloy welded pipeline passes through the pipeline auxiliary positioning groove; a pipeline through hole is provided on the top of the pipeline micro-straightening reaction force support seat, and the alignment section of the titanium alloy welded pipeline is located in the pipeline through hole, and the pipeline micro-straightening force screw is vertically installed on the pipeline micro-straightening reaction force support seat above the pipeline through hole, and the pipeline micro-straightening force screw is in contact with the alignment section of the titanium alloy welded pipeline.

[0018] When the titanium alloy welded pipeline needs micro-straightening, the micro-straightening tool is used. First, the titanium alloy welded pipeline to be straightened passes between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support, then passes through the pipeline through-hole of the pipeline micro-straightening reaction force support seat, and then passes through the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat until the straightening section of the titanium alloy welded pipeline is in the pipeline through-hole of the pipeline micro-straightening reaction force support seat, then tighten the micro-straightening pipeline fixing clamping screw to straighten the titanium alloy welded pipeline. The non-shaping section on one side of the pipeline is pressed and fixed between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support, and finally the pipeline micro-straightening force screw is screwed to apply radial thrust to the shaping section of the titanium alloy welded pipeline until the cold shaping of the shaping section of the titanium alloy welded pipeline is completed. During the cold shaping process, the non-shaping section on the other side of the titanium alloy welded pipeline will only slide axially in the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat. At this time, the cold shaping and positioning work of the titanium alloy welded pipeline is completed.

[0019] The micro-bend tooling includes a micro-bend tooling base plate, a micro-bend pipeline fixing support, a micro-bend pipeline fixing pressure plate, a micro-bend pipeline fixing clamping screw, a micro-bend pipeline positioning support seat, a micro-bend pipeline positioning sleeve, a micro-bend pipeline positioning sleeve, a micro-bend pipeline guide limit screw and a micro-bend pipeline clamping screw; the micro-bend pipeline fixing support is fixedly installed on the upper surface of the micro-bend tooling base plate, and the micro-bend pipeline fixing pressure plate is arranged on the top of the micro-bend pipeline fixing support, and the micro-bend pipeline fixing pressure plate and the micro-bend pipeline fixing support are connected by the micro-bend pipeline fixing clamping screw, and the non-bend section of the titanium alloy welded pipeline passes between the micro-bend pipeline fixing pressure plate and the micro-bend pipeline fixing support; the micro-bend pipeline positioning support seat is fixedly installed on the upper surface of the micro-bend tooling base plate, and the micro-bend pipeline positioning support seat and the micro-bend pipeline fixing support are connected by the micro-bend pipeline fixing clamping screw. There is an angle between the central axes of the bent pipe fixing supports; the micro-bend pipe positioning sleeve is fixedly installed in the micro-bend pipe positioning support seat, and the micro-bend pipe positioning sleeve is coaxially installed in the micro-bend pipe positioning sleeve, and the micro-bend pipe positioning sleeve has only axial freedom of movement relative to the micro-bend pipe positioning sleeve; a guide oblong hole is opened on the upper cylinder wall of the micro-bend pipe positioning sleeve, and the micro-bend pipe guide limit screw is vertically installed on the top of the micro-bend pipe positioning support seat, and the micro-bend pipe guide limit screw extends into the guide oblong hole; the non-aligned section of the titanium alloy welded pipeline is coaxially inserted into the micro-bend pipe positioning sleeve; the micro-bend pipe clamping screw is installed on the cylinder wall of the micro-bend pipe positioning sleeve, and the micro-bend pipe clamping screw is in contact with the non-aligned section of the titanium alloy welded pipeline.

[0020] When the titanium alloy welded pipeline needs micro-bending, a micro-bending tool is used. First, the non-bending section on one side of the titanium alloy welded pipeline to be shaped is passed between the micro-bending pipeline fixed pressure plate and the micro-bending pipeline fixed support until the pipe mouth of the non-bending section on the other side of the titanium alloy welded pipeline is in front of the tube mouth of the micro-bending pipeline positioning sleeve. Then, the micro-bending pipeline fixing and tightening screws are tightened to fix the non-bending section on one side of the titanium alloy welded pipeline between the micro-bending pipeline fixed pressure plate and the micro-bending pipeline fixed support. Then, external force is applied to the non-bending section on the other side of the titanium alloy welded pipeline to complete the cold shaping of the shaping section of the titanium alloy welded pipeline, and at the same time, the titanium The pipe mouth of the non-correcting section on the other side of the alloy welded pipeline is coaxial with the tube mouth of the micro-correcting bend pipeline positioning sleeve, and then the micro-correcting bend pipeline positioning sleeve is pushed forward axially until the non-correcting section on the other side of the titanium alloy welded pipeline is inserted into the micro-correcting bend pipeline positioning sleeve. At this time, the external force applied to the non-correcting section on the other side of the titanium alloy welded pipeline is removed. Restricted by the micro-correcting bend pipeline positioning sleeve, the cold-correcting state of the titanium alloy welded pipeline shaping section can still be maintained. Finally, tighten the micro-correcting bend pipeline tightening screw to fix the non-correcting section on the other side of the titanium alloy welded pipeline and the micro-correcting bend pipeline positioning sleeve together. At this time, the cold-correcting and positioning work of the titanium alloy welded pipeline is completed.

[0021] The beneficial effects of the present application are:

[0022] The aviation engine titanium alloy welded pipeline pulse current auxiliary micro-straightening method of the present application introduces the pulse current auxiliary forming technology into the micro-straightening of the titanium alloy pipeline, generates the Joule heat effect and the electroplastic effect in the local area where the straightening section of the titanium alloy pipeline is located through the pulse current, can avoid the deterioration of the microstructure and mechanical properties of the titanium alloy pipeline as a whole, and greatly improves the straightening efficiency and straightening accuracy of the titanium alloy pipeline. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structural schematic view of the micro-straightening tool of the present application (view angle one);

[0024] Figure 2 It is a structural schematic view of the micro-straightening tool of the present application (view angle two);

[0025] Figure 3 It is a structural schematic view of the micro-bending tool of the present application (view angle one);

[0026] Figure 4 It is a structural schematic view of the micro-bending tool of the present application (view angle two);

[0027] In the figure, 1 is a titanium alloy welded pipeline, 2 is a first electrode, 3 is a second electrode, 4 is a direct current pulse power supply, 5 is a micro-straightening tool bottom plate, 6 is a micro-straightening pipeline fixed support, 7 is a micro-straightening pipeline fixed pressing plate, 8 is a micro-straightening pipeline fixed pressing screw, 9 is a micro-straightening pipeline auxiliary positioning support seat, 10 is a pipeline micro-straightening counter-force support seat, 11 is a pipeline micro-straightening force applying screw, 12 is a micro-bending tool bottom plate, 13 is a micro-bending pipeline fixed support, 14 is a micro-bending pipeline fixed pressing plate, 15 is a micro-bending pipeline fixed pressing screw, 16 is a micro-bending pipeline positioning support seat, 17 is a micro-bending pipeline positioning sliding sleeve, 18 is a micro-bending pipeline positioning sleeve, 19 is a micro-bending pipeline guide limiting screw, 20 is a micro-bending pipeline pressing screw, and 21 is a guide long circular hole. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0029] An aviation engine titanium alloy welded pipeline pulse current auxiliary micro-straightening method, comprising the following steps:

[0030] Step one: manufacturing a straightening tool;

[0031] Step two: fixing and clamping the titanium alloy welded pipeline 1 into the straightening tool, and at the same time, completing the cold straightening positioning of the titanium alloy welded pipeline 1;

[0032] Step three: install the first electrode 2 and the second electrode 3 at both ends of the shaping section of the titanium alloy welded pipeline 1 respectively;

[0033] Step four: connect the first electrode 2 and the second electrode 3 to the positive and negative poles of the direct current pulse power supply 4 through wires respectively;

[0034] Step five: start the direct current pulse power supply 4 to heat the shaping section of the titanium alloy welded pipeline 1 through pulse current;

[0035] Step six: real-time temperature measurement of the shaping section of the titanium alloy welded pipeline 1 through the temperature measuring instrument until the real-time temperature of the shaping section of the titanium alloy welded pipeline 1 reaches the set value;

[0036] Step seven: holding the shaping section of the titanium alloy welded pipeline 1 at the set temperature value for a set time;

[0037] Step eight: turn off the direct current pulse power supply 4 to end the heating of the shaping section of the titanium alloy welded pipeline 1 until the temperature of the shaping section of the titanium alloy welded pipeline 1 cools to room temperature;

[0038] Step nine: remove the titanium alloy welded pipeline 1 from the shaping tool, and the pulse current assisted micro-shaping of the titanium alloy welded pipeline 1 is completed.

[0039] The shaping tool is divided into a micro-straightening tool and a micro-bending tool.

[0040] As Figure 1 , 2As shown, the micro-straightening fixture includes a micro-straightening fixture base plate 5, a micro-straightening pipeline fixed support 6, a micro-straightening pipeline fixed pressure plate 7, a micro-straightening pipeline fixed tightening screw 8, a micro-straightening pipeline auxiliary positioning support seat 9, a pipeline micro-straightening reaction force support seat 10 and a pipeline micro-straightening force screw 11; the micro-straightening pipeline fixed support 6, the pipeline micro-straightening reaction force support seat 10 and the micro-straightening pipeline auxiliary positioning support seat 9 are fixedly installed on the upper surface of the micro-straightening fixture base plate 5 in a straight line sequence; the micro-straightening pipeline fixed pressure plate 7 is arranged on the top of the micro-straightening pipeline fixed support 6, and the micro-straightening pipeline fixed pressure plate 7 and the micro-straightening pipeline fixed support 6 are connected by the micro-straightening pipeline fixed tightening screw 8, The non-alignment section of the titanium alloy welded pipeline 1 passes between the micro-straightening pipeline fixed pressure plate 7 and the micro-straightening pipeline fixed support 6; a pipeline auxiliary positioning groove is provided on the top of the micro-straightening pipeline auxiliary positioning support seat 9, and the non-alignment section of the titanium alloy welded pipeline 1 passes through the pipeline auxiliary positioning groove; a pipeline through hole is provided on the top of the pipeline micro-straightening reaction force support seat 10, and the alignment section of the titanium alloy welded pipeline 1 is located in the pipeline through hole, and the pipeline micro-straightening force screw 11 is vertically installed on the pipeline micro-straightening reaction force support seat 10 above the pipeline through hole, and the pipeline micro-straightening force screw 11 is in contact with the alignment section of the titanium alloy welded pipeline 1.

[0041] When the titanium alloy welding pipeline 1 needs micro-straightening, a micro-straightening tool is used. First, the titanium alloy welding pipeline 1 to be straightened is passed between the micro-straightening pipeline fixed pressure plate 7 and the micro-straightening pipeline fixed support 6, and then passed through the pipeline through-hole of the pipeline micro-straightening reaction force support seat 10, and then passed through the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat 9, until the straightening section of the titanium alloy welding pipeline 1 is in the pipeline through-hole of the pipeline micro-straightening reaction force support seat 10, and then tighten the micro-straightening pipeline fixing tightening screw 8 to straighten the titanium alloy welding pipeline 1. The non-shaping section on one side of the pipe 1 is pressed and fixed between the micro-straightening pipe fixed pressure plate 7 and the micro-straightening pipe fixed support 6, and finally the pipe micro-straightening force screw 11 is screwed to apply radial thrust to the shaping section of the titanium alloy welded pipe 1 until the cold shaping of the shaping section of the titanium alloy welded pipe 1 is completed. During the cold shaping process, the non-shaping section on the other side of the titanium alloy welded pipe 1 will only slide axially in the pipe auxiliary positioning groove of the micro-straightening pipe auxiliary positioning support seat 9. At this time, the cold shaping and positioning work of the titanium alloy welded pipe 1 is completed.

[0042] Example 1

[0043] In this embodiment, the titanium alloy welded pipe 1 needs to be slightly straightened. The initial straightness of the titanium alloy welded pipe 1 before straightening is 1.8 mm, and the target straightness of the titanium alloy welded pipe 1 after straightening is ±0.3 mm. During the cold straightening positioning, the cold deformation of the straightening section of the titanium alloy welded pipe 1 is adjusted to 2.3 mm by screwing the pipe micro-straightening force screw 11. In the subsequent heating stage, the pulse current is set to 5 A / mm 2 The set heating temperature is 500℃, the holding time is 2min, and the straightness of the titanium alloy welded pipe 1 is measured after correction. The straightness measurement result is 0.2mm, which meets the design requirements.

[0044] like Figure 3 、 4 As shown, the micro-bend tooling includes a micro-bend tooling base plate 12, a micro-bend pipeline fixing support 13, a micro-bend pipeline fixing pressure plate 14, a micro-bend pipeline fixing clamping screw 15, a micro-bend pipeline positioning support seat 16, a micro-bend pipeline positioning sleeve 17, a micro-bend pipeline positioning sleeve 18, a micro-bend pipeline guide limit screw 19 and a micro-bend pipeline clamping screw 20; the micro-bend pipeline fixing support 13 is fixedly mounted on the upper surface of the micro-bend tooling base plate 12, and the micro-bend pipeline fixing pressure plate 14 is fixed on the upper surface of the micro-bend tooling base plate 12. The bend pipe fixing plate 14 is arranged on the top of the micro-bend pipe fixing support 13, and the micro-bend pipe fixing plate 14 and the micro-bend pipe fixing support 13 are connected by the micro-bend pipe fixing tightening screw 15. The non-bend section of the titanium alloy welded pipeline 1 passes through between the micro-bend pipe fixing plate 14 and the micro-bend pipe fixing support 13; the micro-bend pipe positioning support seat 16 is fixedly installed on the upper surface of the micro-bend tooling bottom plate 12, and the micro-bend pipe positioning support seat There is an angle between 16 and the central axis of the micro-calibration bend pipeline fixed support 13; the micro-calibration bend pipeline positioning sleeve 17 is fixedly installed in the micro-calibration bend pipeline positioning support seat 16, and the micro-calibration bend pipeline positioning sleeve 18 is coaxially installed inside the micro-calibration bend pipeline positioning sleeve 17. The micro-calibration bend pipeline positioning sleeve 18 has only axial freedom of movement relative to the micro-calibration bend pipeline positioning sleeve 17; a guide oblong hole 21 is opened on the upper wall of the micro-calibration bend pipeline positioning sleeve 18, so The micro-bend pipeline guide limit screw 19 is vertically installed on the top of the micro-bend pipeline positioning support seat 16, and the micro-bend pipeline guide limit screw 19 extends into the guide oblong hole 21; the non-alignment section of the titanium alloy welded pipeline 1 is coaxially inserted into the micro-bend pipeline positioning sleeve 18; the micro-bend pipeline clamping screw 20 is installed on the cylinder wall of the micro-bend pipeline positioning sleeve 18, and the micro-bend pipeline clamping screw 20 is in contact with the non-alignment section of the titanium alloy welded pipeline 1.

[0045] When the titanium alloy welding pipeline 1 needs to be slightly bent, a micro-bending tool is used. First, the non-bending section on one side of the titanium alloy welding pipeline 1 to be shaped is passed between the micro-bending pipeline fixed pressure plate 14 and the micro-bending pipeline fixed support 13 until the pipe mouth of the non-bending section on the other side of the titanium alloy welding pipeline 1 is in front of the tube mouth of the micro-bending pipeline positioning sleeve 18, and then the micro-bending pipeline fixing tightening screw 15 is tightened to press and fix the non-bending section on one side of the titanium alloy welding pipeline 1 between the micro-bending pipeline fixed pressure plate 14 and the micro-bending pipeline fixed support 13, and then external force is applied to the non-bending section on the other side of the titanium alloy welding pipeline 1 to complete the cold shaping of the shaping section of the titanium alloy welding pipeline 1, and at the same time, the titanium The pipe mouth of the non-shaping section on the other side of the alloy welding pipeline 1 is coaxial with the pipe mouth of the micro-bend pipeline positioning sleeve 18, and then the micro-bend pipeline positioning sleeve 18 is pushed forward axially until the non-shaping section on the other side of the titanium alloy welding pipeline 1 is inserted into the micro-bend pipeline positioning sleeve 18. At this time, the external force applied to the non-shaping section on the other side of the titanium alloy welding pipeline 1 is removed. Due to the restriction of the micro-bend pipeline positioning sleeve 18, the cold-shaping state of the shaping section of the titanium alloy welding pipeline 1 can still be maintained. Finally, the micro-bend pipeline tightening screw 20 is tightened to fix the non-shaping section on the other side of the titanium alloy welding pipeline 1 and the micro-bend pipeline positioning sleeve 18 together. At this time, the cold-shaping and positioning work of the titanium alloy welding pipeline 1 is completed.

[0046] Example 2

[0047] In this embodiment, the titanium alloy welding pipeline 1 needs to be slightly bent. During the cold shaping and positioning, the angle between the central axis of the micro-bend pipeline positioning support seat 16 and the micro-bend pipeline fixed support 13 is set to 129°. The initial bending angle of the titanium alloy welding pipeline 1 before shaping is 132°, and the target bending angle after shaping is 130°. The allowable error is ±0.5°. By applying external force, the bending angle of the titanium alloy welding pipeline 1 is cold-shaped to 129°, that is, the cold deformation amount is adjusted to 3°, and the micro-bend pipeline positioning sleeve 18 is used for positioning and fixing. In the subsequent heating stage, the pulse current is set to 5A / mm 2 The heating setting temperature is 500℃, the holding time is 2min, and the bending angle of the titanium alloy welded pipe 1 is measured after correction. The bending angle measurement result is 130.3°, which meets the design requirements.

[0048] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the scope of protection of the present invention are included in the scope of protection of the present invention.

Claims

1. A pulse current assisted micro-straightening method for titanium alloy welding pipelines of aircraft engines, characterized in that: The steps include: Step 1: Manufacturing a shaping tool; the shaping tool is divided into a micro-straightening tool and a micro-bending tool; The micro-straightening tool comprises a micro-straightening tool base plate, a micro-straightening pipeline fixed support, a micro-straightening pipeline fixed pressure plate, a micro-straightening pipeline fixed tightening screw, a micro-straightening pipeline auxiliary positioning support seat, a pipeline micro-straightening reaction force support seat and a pipeline micro-straightening force screw; the micro-straightening pipeline fixed support, the pipeline micro-straightening reaction force support seat and the micro-straightening pipeline auxiliary positioning support seat are fixedly installed on the upper surface of the micro-straightening tool base plate in a straight line sequence; the micro-straightening pipeline fixed pressure plate is arranged on the top of the micro-straightening pipeline fixed support, and the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support are connected by the micro-straightening pipeline fixed tightening screw, the titanium The non-alignment section of the alloy welded pipeline passes through between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support; a pipeline auxiliary positioning groove is provided on the top of the micro-straightening pipeline auxiliary positioning support seat, and the non-alignment section of the titanium alloy welded pipeline passes through the pipeline auxiliary positioning groove; a pipeline through hole is provided on the top of the pipeline micro-straightening reaction force support seat, and the alignment section of the titanium alloy welded pipeline is located in the pipeline through hole, and the pipeline micro-straightening force screw is vertically installed on the pipeline micro-straightening reaction force support seat above the pipeline through hole, and the pipeline micro-straightening force screw is in abutment contact with the alignment section of the titanium alloy welded pipeline; The micro-bend tooling includes a micro-bend tooling base plate, a micro-bend pipeline fixing support, a micro-bend pipeline fixing pressure plate, a micro-bend pipeline fixing clamping screw, a micro-bend pipeline positioning support seat, a micro-bend pipeline positioning sleeve, a micro-bend pipeline positioning sleeve, a micro-bend pipeline guide limit screw and a micro-bend pipeline clamping screw; the micro-bend pipeline fixing support is fixedly installed on the upper surface of the micro-bend tooling base plate, and the micro-bend pipeline fixing pressure plate is arranged on the top of the micro-bend pipeline fixing support, and the micro-bend pipeline fixing pressure plate and the micro-bend pipeline fixing support are connected by the micro-bend pipeline fixing clamping screw, and the non-bend section of the titanium alloy welded pipeline passes between the micro-bend pipeline fixing pressure plate and the micro-bend pipeline fixing support; the micro-bend pipeline positioning support seat is fixedly installed on the upper surface of the micro-bend tooling base plate, and the micro-bend pipeline positioning support seat and the micro-bend pipeline fixing support are connected by the micro-bend pipeline fixing clamping screw. There is an angle between the central axes of the curved pipe fixing supports; the micro-calibration curved pipe positioning sleeve is fixedly installed in the micro-calibration curved pipe positioning support seat, and the micro-calibration curved pipe positioning sleeve is coaxially installed inside the micro-calibration curved pipe positioning sleeve, and the micro-calibration curved pipe positioning sleeve has only axial freedom of movement relative to the micro-calibration curved pipe positioning sleeve; a guide oblong hole is opened on the upper cylinder wall of the micro-calibration curved pipe positioning sleeve, and the micro-calibration curved pipe guide limit screw is vertically installed on the top of the micro-calibration curved pipe positioning support seat, and the micro-calibration curved pipe guide limit screw extends into the guide oblong hole; the non-calibration section of the titanium alloy welded pipeline is coaxially inserted and matched with the micro-calibration curved pipe positioning sleeve; the micro-calibration curved pipe clamping screw is installed on the cylinder wall of the micro-calibration curved pipe positioning sleeve, and the micro-calibration curved pipe clamping screw is in contact with the non-calibration section of the titanium alloy welded pipeline; Step 2: Fix the titanium alloy welded pipe into the shaping fixture and complete the cold shaping positioning of the titanium alloy welded pipe at the same time; Step 3: Install a first electrode and a second electrode at both ends of the shaping section of the titanium alloy welding pipe; Step 4: Connect the first electrode and the second electrode to the positive and negative poles of a DC pulse power supply respectively through wires; Step 5: Start the DC pulse power supply and heat the shaping section of the titanium alloy welding pipe through the pulse current; Step 6: Use a thermometer to measure the temperature of the shaping section of the titanium alloy welded pipe in real time until the real-time temperature of the shaping section of the titanium alloy welded pipe reaches the set value; Step 7: Keep the shaped section of the titanium alloy welded pipe at the set temperature for a set time; Step 8: Turn off the DC pulse power supply to end the heating of the titanium alloy welding pipe shaping section until the temperature of the titanium alloy welding pipe shaping section cools to room temperature; Step 9: Remove the titanium alloy welding pipe from the shaping tooling, and the pulse current assisted micro-shaping of the titanium alloy welding pipe is completed.

2. The pulse current assisted micro-straightening method for titanium alloy welding pipelines for aircraft engines according to claim 1, characterized in that: When the titanium alloy welded pipeline needs micro-straightening, the micro-straightening tool is used. First, the titanium alloy welded pipeline to be straightened passes between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support, then passes through the pipeline through-hole of the pipeline micro-straightening reaction force support seat, and then passes through the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat until the straightening section of the titanium alloy welded pipeline is in the pipeline through-hole of the pipeline micro-straightening reaction force support seat, then tighten the micro-straightening pipeline fixing clamping screw to straighten the titanium alloy welded pipeline. The non-shaping section on one side of the pipeline is pressed and fixed between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support, and finally the pipeline micro-straightening force screw is screwed to apply radial thrust to the shaping section of the titanium alloy welded pipeline until the cold shaping of the shaping section of the titanium alloy welded pipeline is completed. During the cold shaping process, the non-shaping section on the other side of the titanium alloy welded pipeline will only slide axially in the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat. At this time, the cold shaping and positioning work of the titanium alloy welded pipeline is completed.

3. The pulse current assisted micro-straightening method for titanium alloy welding pipelines for aircraft engines according to claim 1, characterized in that: When the titanium alloy welded pipeline needs micro-bending, a micro-bending tool is used. First, the non-bending section on one side of the titanium alloy welded pipeline to be shaped is passed between the micro-bending pipeline fixed pressure plate and the micro-bending pipeline fixed support until the pipe mouth of the non-bending section on the other side of the titanium alloy welded pipeline is in front of the tube mouth of the micro-bending pipeline positioning sleeve. Then, the micro-bending pipeline fixing and tightening screws are tightened to fix the non-bending section on one side of the titanium alloy welded pipeline between the micro-bending pipeline fixed pressure plate and the micro-bending pipeline fixed support. Then, external force is applied to the non-bending section on the other side of the titanium alloy welded pipeline to complete the cold shaping of the shaping section of the titanium alloy welded pipeline, and at the same time, the titanium The pipe mouth of the non-correcting section on the other side of the alloy welded pipeline is coaxial with the tube mouth of the micro-correcting bend pipeline positioning sleeve, and then the micro-correcting bend pipeline positioning sleeve is pushed forward axially until the non-correcting section on the other side of the titanium alloy welded pipeline is inserted into the micro-correcting bend pipeline positioning sleeve. At this time, the external force applied to the non-correcting section on the other side of the titanium alloy welded pipeline is removed. Restricted by the micro-correcting bend pipeline positioning sleeve, the cold-correcting state of the titanium alloy welded pipeline shaping section can still be maintained. Finally, tighten the micro-correcting bend pipeline tightening screw to fix the non-correcting section on the other side of the titanium alloy welded pipeline and the micro-correcting bend pipeline positioning sleeve together. At this time, the cold-correcting and positioning work of the titanium alloy welded pipeline is completed.

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